The development of 5G capabilities for smartphones is a step on the way to advanced use of cellular communications in autonomous vehicles (Reuters, Tom's Guide, Digital Trends). Smartphones with physical 5G add-on capabilities (e.g., Verizon's Moto Z3) will not count unless the required physical add-ons are also offered. For the purposes of this question, should the merger between Sprint and T-Mobile close the companies will continue to be counted separately.